Densités et biomasses de Camponotus acvapimensis (Hym. formicidæ) dans une savane de Côte-d’Ivoire

L’étude quantitative des populations de Camponotus acvapi mensis, espèce de fourmi la plus abondante dans une savane de Côte-d’Ivoire, a permis d’évaluer les effectifs et les biomasses de chacune des castes de l’espèce dans les divers faciès pédologiques. A titre d’exemple, on a estimé à 2,2 X 106 ouvrières, 1,1 X 105 mâles, 9 X 104 femelles et 6,9 X 105 larves les densités à l’hectare dans les sols argileux, domaine de prédilection de l’espèce (Tableaux la, I b et le). Ceci fournit des biomasses respectives en poids frais de 1,42 g/m2 pour les ouvrières, 0,2 g/m2 pour les sexués et 0,6 g/m2 pour les larves. Les poids secs équivalents sont de 0,35, 0,04 et 0,12 g/m2. Les équivalents énergétiques des bio masses étant de 6,321 ± 0,185 kcal/g pour les ouvrières et de 5,499 ± 0,166 kcal/g pour les larves, la biomasse totale de C. acvapimensis représente une valeur énergétique de 3,200 kcal/m2. L’étude de l’implantation et de la densité par hectare des sociétés et des femelles essaimantes montre que l’espace est le facteur limitant l’expansion de cette fourmi ; aussi les sociétés tendent-elles à se remplacer nombre par nombre.Camponotus acvapimensis is the commonest species of terri- colous ant found in the Lamto savanna of the Ivory Coast. Esti mates of the population densities and standing crop biomasses for each cast have been made for the three major soil categories (Tables I a - c). The standing crop biomass (dry weight) of this species of ant averages 0.52 g/m2 in black soils, 0.47 g/m2 in ferralitic soils and 0.20 g/m2 in hydromorphic soils (Table II). The lack of suitable space appears to be the major limiting factor for the establishment of new colonies

The meaning of community and participation in public service delivery : whose interests are served?

Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.The relative autonomy of the State is a long historical debate. In the current South African context, national policy documents reflect the State as working in the interests of the common good. The complex process of policy implementation, however, would suggest that the relationship between policy goals and policy outcomes is neither linear nor certain. Rather it is determined by a range of factors particularly at the implementation level. Moreover, the success of projects which employ participatory processes are dependent on how participation is conceived. The Hill Street West case study is an attempt to address the question of whether local government acts in the interests of the common or public good or on behalf of vested interests. The use of key informant interviews, documentary data and a short attitudinal survey have shown that the local state chose to act on behalf of a vested interest, arguing that it would also serve the common good. The findings would suggest that this was not the outcome and that ultimately, neither sectoral nor the general interest were adequately served. The outcome is attributable in large measure to underlying interests within the local state agenda with implications for the usefulness of participation

A quantitative PCR method to quantify ruminant DNA in porcine crude heparin

Heparin is a well-known glycosaminoglycan extracted from porcine intestines. Increased vigilance for transmissible spongiform encephalopathy in animal-derived pharmaceuticals requires methods to prevent the introduction of heparin from ruminants into the supply chain. The sensitivity, specificity, and precision of the quantitative polymerase chain reaction (PCR) make it a superior analytical platform for screening heparin raw material for bovine-, ovine-, and caprine-derived material. A quantitative PCR probe and primer set homologous to the ruminant Bov-A2 short interspersed nuclear element (SINE) locus (Mendoza-Romero et al. J. Food Prot. 67:550–554, 2004) demonstrated nearly equivalent affinities for bovine, ovine, and caprine DNA targets, while exhibiting no cross-reactivity with porcine DNA in the quantitative PCR method. A second PCR primer and probe set, specific for the porcine PRE1 SINE sequence, was also developed to quantify the background porcine DNA level. DNA extraction and purification was not necessary for analysis of the raw heparin samples, although digestion of the sample with heparinase was employed. The method exhibits a quantitation range of 0.3–3,000 ppm ruminant DNA in heparin. Validation parameters of the method included accuracy, repeatability, precision, specificity, range, quantitation limit, and linearity

Structure-based mechanism of hydratase-aldolases in the Type I aldolase superfamily and structures of tautomerase superfamily members

Polycyclic Aromatic Hydrocarbons (PAHs) are composed of multiple benzene-like rings and their bacterial catabolism has potential utility for bioremediation. In the breakdown of each ring, oxygenation is followed by ring cleavage and side chain removal, the latter of which is catalyzed by hydratase-aldolases. These enzymes belong to the N-acetylneuraminate lyase (NAL) subgroup of the Type I aldolase superfamily. NahE and PhdJ are hydratase-aldolases that process benzylidenepyruvate compounds in PAH degradative pathways from Pseudomonas putida G7 and Mycobacterium vanbaalenii PYR-1, respectively. Crystal structures of these enzymes in liganded and unliganded states are reported here and reveal new details about their catalytic mechanisms. Stabilization of the developing hydroxide anion during hydration could involve the amide nitrogen of Asn-157 (NahE numbering), conserved in hydratase-aldolases, but not other NAL subgroup members. For NahE, Tyr-155 might act as the general base for addition, but the identity of the base is less certain for PhdJ. The crystal structure of PhdG reveals a carbinolamine intermediate hydrogen bonding to Tyr-152, consistent with the participation of the residue in Schiff base formation. In addition, this dissertation describes structures within the tautomerase superfamily (TSF). The enzymes reported are from 4-oxalocrotonate tautomerase (4-OT), cis-3-chloroacrylic acid dehalogenase (cis-CaaD), and malonate semialdehyde decarboxylase (MSAD) subgroups. 4-OT catalyzes the ketonization of 2-hydroxymuconate (2-HM) in the meta-fission pathway. cis-CaaD and MSAD respectively catalyze dehalogenation and decarboxylation reactions in the catabolic 1,3-dichloropropene pathway, respectively. TSF members have a catalytic Pro-1 and share a common β-α-β fold. TSF members designated Ps01740, Pt0534, and Fused 4-OT have sequence similarity with the cis-CaaD and 4-OT subgroups and may provide insight into gene duplication and fusion events in the TSF. These enzymes have tautomerase activity and low or absent cis-CaaD activity. Liganded and unliganded structures suggest a structural basis for their activation. The trimeric structure of Fused 4-OT is unusual in that one monomer is inverted relative to the others. Mechanisms for 2-HM tautomerization are proposed based on a 2-HM-bound structure and kinetic parameters of mutants. Crystal structures for the MSAD homologues BP4401 and YusQ were obtained, and provide clues about their activitiesBiochemistr

Process assessment issues in a bachelor capstone project

Based on a small subset of ISO/IEC 15504:2006, a Process Assessment was performed in the capstone project of a Bachelor in Computer Science. Parallel to this assessment, students performed a continuous self-assessment using an ability model based on 15504 Base Practices and Work Products. This paper highlights how students' self- assessment and teacher's assessment are correlated. The capstone project itself implements major constructivism principles. This paper presents also the students’ point of view through different questionnaires and students’ participation to the paper

Compliance with the current recommendations for prescribing antibiotics for paediatric community-acquired pneumonia is improving: data from a prospective study in a French network

International audienceBACKGROUND: Lower respiratory tract infection is a common cause of consultation and antibiotic prescription in paediatric practice. The misuse of antibiotics is a major cause of the emergence of multidrug-resistant bacteria. The aim of this study was to evaluate the frequency, changes over time, and determinants of non-compliance with antibiotic prescription recommendations for children admitted in paediatric emergency department (PED) with community-acquired pneumonia (CAP).METHODS: We conducted a prospective two-period study using data from the French pneumonia network that included all children with CAP, aged one month to 15 years old, admitted to one of the ten participating paediatric emergency departments. In the first period, data from children included in all ten centres were analysed. In the second period, we analysed children in three centers for which we collected additional data. Two experts assessed compliance with the current French recommendations. Independent determinants of non-compliance were evaluated using a logistic regression model. The frequency of non-compliance was compared between the two periods for the same centres in univariate analysis, after adjustment for confounding factors.RESULTS: A total of 3034 children were included during the first period (from May 2009 to May 2011) and 293 in the second period (from January to July 2012). Median ages were 3.0 years [1.4-5] in the first period and 3.6 years in the second period. The main reasons for non-compliance were the improper use of broad-spectrum antibiotics or combinations of antibiotics. Factors that were independently associated with non-compliance with recommendations were younger age, presence of risk factors for pneumococcal infection, and hospitalization. We also observed significant differences in compliance between the treatment centres during the first period. The frequency of non-compliance significantly decreased from 48 to 18.8 % between 2009 and 2012. The association between period and non-compliance remained statistically significant after adjustment for confounding factors. Amoxicillin was prescribed as the sole therapy significantly more frequently in the second period (71 % vs. 54.2 %, p < 0.001).CONCLUSIONS: We observed a significant increase in the compliance with recommendations, with a reduction in the prescription of broad-spectrum antibiotics, efforts to improve antibiotic prescriptions must continue

Transient self-potential anomalies associated with recent lava flows at Piton de la Fournaise volcano (Réunion Island, Indian Ocean)

International audienceSelf-potential signals are sensitive to various phenomena including ground water flow (streaming potential), thermal gradients (thermoelectric potential), and potentially rapid fluid disruption associated with vaporization of water. We describe transient self-potential anomalies observed over recent (< 9 years) lava flows at Piton de la Fournaise volcano (Reunion Island, Indian Ocean). Repeated self-potential measurements are used to determine the decay of the self-potential signals with time since the emplacement of a set of lava flow. We performed a 9 km-long self-potential profile in February 2004 in the Grand Brûlé area. This profile was repeated in July–August 2006. The second repetition of this profile crossed eight lava flows emplaced between 1998 and 2005 during seven eruptions of Piton de la Fournaise volcano. The self-potential data show clear positive anomalies (up to 330 mV) and spatially correlated with the presence of recent lava flows. The amplitude of the self-potential anomalies decreases exponentially with the age of the lava flows with a relaxation time of not, vert, similar 44 months. We explain these anomalies by the shallow convection of meteoric water and the associated streaming potential distribution but we cannot exclude possible contributions from the thermoelectric effect and the rapid fluid disruption mechanism. This field case evidences for the first time transient self-potential signals associated with recent volcanic deposits. It can be also a shallow analogue to understand the variation of self-potential signals in active geothermal areas and transient self-potential signals associated with dike intrusion at larger depths. The empirical equation we proposed can also be used to diagnose the cooling of recent lava flow on shield volcanoes

Determination of Lactoferrin and Immunoglobulin G in Animal Milks by New Immunosensors

Two different immunosensors, recently developed for the determination of antibacterial proteins (lactoferrin and immunoglobulin G) in buffalo milk and in other commercial animal milks samples, were used in the present study. The aim was to propose these immunosensor methods for routine control of important diet products, such as cow and goat milks, and in particular buffalo milk. To this end we employed two different kinds of immunosensors: one for the analysis of immunoglobulin G (IgG), the other was a new amperometric immunosensor for lactoferrin analysis. Lactoferrin and IgG immunosensors were also used for the determination of lactoferrin and immunoglobulin G in buffalo milk on different days of lactation